Solar cells which convert radiant energy from the sun into electrical energy are used to power spacecraft. Designers of power systems for this application face numerous design constraints of which weight is one of the most critical. The extraordinarily high cost of placing a pound of weight into space is a serious constraint, and any improvement which can reduce the weight and still provide adequate performance is actively sought.
Another constraint is the need for shielding the solar cells against radiation in regions of high fluence. An example is found in Van Allen belt radiation at about 7,000 kilometers elevation, which is where many satellites orbit. It is not uncommon to apply a shielding layer of sufficient density over an entire craft merely in order to protect some parts of if, especially the solar cells. This significantly increases the weight of the craft. Any arrangement which can reduce the area or volume that must be shielded is also actively sought.
Still another constraint Is the large cost of the solar cells. These cells often are as much as 60% of the cost of the entire solar array. Reduction of required cell area, while still obtaining the same power output, is another sought-after advantage.
Yet another constraint is the volume required to pack a solar cell array into a spacecraft for containment while being launched. Reduction of stowed envelope volume is another design objective.
This invention provides an improvement for all of the above design constraints and objectives. It requires a lesser area of cells for the same net incident sunlight area, and provides a configuration stowable in a lesser volume that is readily deployable to a larger volume in which its elements are properly arranged relative to one another. The consequence is a significant reduction of weight for the same kilowatt output, especially for those missions requiring significant shielding thickness. A further consequence is that the reduced area of cells can reduce array costs.